The Proteomics Facility Core is designed to develop, adopt, and maintain state-of-the-art expertise and equipment for studies in proteomics, and to provide unique antibodies against xenobiotic metabolizing enzymes and their transporters for use by Center members. The core provides proteomic services including 2-D gels, fluorescent 2-D-difference gel electrophoresis for simultaneous quantification of the differences between treated and untreated tissues or cells in hundreds of individual proteins, and identification of these proteins by mass spectrometry of protease digested spots. In addition, the facility core provides access to and experience in the use of a unique and growing library of over 100 monoclonal and polyclonal antibodies specific for different xenobiotic metabolizing enzymes and their transporters.